Figure



March 31, 1964 H. L. SHOVE FORCED AIR COOLED REFRIGERATOR Filed Oct. 26, 1961 3 Sheets-Sheet 1 F'lGJ F'IG.4

INVENTOR.

L. SHOVE HENRY H15 ATTORNEY March 31, 1964 s ov 3,126,721

FORCED AIR COOLED REFRIGERATOR Filed Oct. 26, 1961 3 Sheets-Sheet 2 F'IG.2

INVEN TOR. HENRY 1.. SHOVE.

H15 ATTORNEY March 31, 1964 H. L. SHOVE 3,126,721

FORCED AIR COOLED REFRIGERATOR Filed Oct. 26, 1961 S Sheets-Sheet 5 F'IG.5

INVEN TOR.

HENRY L. suave H l S ATTORNEY United States Patent ()ii ice 3,126,721 Patented Mar. 31, 1964 3,126,721 FGRQED Am CUQLED REFRIGERATGR Henry L. Shove, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Get. 26, 19st, Ser. No. 147,816 4 Claims. (@l. o2--4tl8) The present invention relates to refrigerators and is more particularly concerned with refrigerators containing at least one compartment maintained at a desired operating temperature by means of forced air circulated over an evaporator and improved means tor regulating the temperature of the compartment.

Various refrigerators are known or have been proposed in which a storage compartment is maintained at a desired refrigerating temperature by the forced circulation of .air over an evaporator separate from or outside of the compartment and through the compartment. The cooled by the evaporator is introduced into the compartment through one or more inlet ports or openings and the compartment air is withdrawn cfrorn the compartment for circulation over the evaporator through one or more outlet ports or openings. The evaporator is normally operated at temperatures somewhat below the lowest temperature required in the compartment served by the evaporator and the amount of cooling provided for the compartment is controlled by controlling the amount of refrigerated :air flowing through that compartment.

A number of factors must be taken into consideration in designing a forced air cooling system. For example, for a given evaporator operating at a given temperature, the degree of cooling, that is the temperature of the air as it leaves the evaporator, will depend upon the air flow rate over the evaporator which in turn depends upon the capacity of the fan used to circulate the air and the head pressure against which the fan must operate. Ordinarily in refrigerators containing a fresh [food storage compartment operated at temperatures somewhat above freezing for the storage of unfrozen or fresh foods, it is desirable to provide means for varying or regulating the temperature of that compartment over a range of 5 to degrees to suit the individual desires of the user. Also in order to assure satisfactory operation of the refrigerator under difficult ambient temperature conditions or, in other words, to compensate for the greater heat leakage under high ambient temperature conditions, it is necessary to provide for a greater circulation of retrigerated air through the compartment during the summer months than during the winter months. With an evaporator having a substantially fixed operating temperature and a given fan means for circulating air over the evaporator, the most convenient means for controlling or regulating the temperature within the storage compartment comprises changing the amount of air flowing to that compartment. The usual arrangement for .that purpose comprises a damper in the air supply passage by means of which the volume of air flowing into the storage compartment can be regulated. However, a damper in the air supply passage presents a number of problems and disadvantages. In the first place, the actual temperature of the air flowing to the compartment is affected by changes in the damper position. For example, when the damper is nearly closed the rate of air flow over the evaporator is relatively low so that the air delivered by the fan is colder than when the damper is in its fully open position and there is a more rapid air fiow rate over the evaporator. Furthermore, as the position of the damper is changed from the fully closed position towards the open position, there is rapid non-linear change in the air flow rate. Only a slight opening of the damper provides a substantial air flow through the compartment due to the higher head pressure of the fan in operating against a substantially closed damper whereas movement of the damper to a fully open position will provide very little additional air flow through the compartment. In this connection, it has been noted that even a relatively small air leakage past a damper in the air supply duct, such as that resulting from a poor sealing of the damper when in its closed position, may result in an air flow which is 30-40% that of the flow when the damper is fully opened. In addition when the damper in the air inlet line leading from the evaporator to the storage compartment is fully closed, leakage from the ducts connecting the evaporator with the compartment affect the control of the temperature within the compartment and such leaks are even more troublesome because of the higher pressure head of the fan when operating against the closed damper. Such leakage may also result in a loss of control of the compartment temperature either due to seepage of the cooled air through the insulation and into the compartment or due to ambient air being drawn into the compartment by the fan. Such ambient air leakage into the compartment may take place along the gasket or door sealing means or through the insulation surrounding the compartment.

The present invention has as its principal object the provision of a refrigerator including an improved forced air cooling system adapted to provide a more accurate control of the refrigerator storage compartment temperatures.

Another object of the invention is to provide a new and improved forced air cooled refrigerator whereby the volume of air flowing through one or more of the compartments can be varied without affecting the operating characteristics of the remaining components of the refrigera tor.

A further object of the invention is to provide a new and improved forced air cooled refrigerator in which the output of the forced .air cooling means remain substantially constant and independent of the air supplied to the storage compartment of the refrigerator.

A more specific object of the invention is to provide a refrigerator including an improved means for regulating the flow of forced air to a storage compartment thereof.

Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In accordance with the present invention there is provided a refrigerator including a storage compartment, an evaporator separate from that compartment and a duct defining an air iiow passageway outside of the compartment for the flow of air from the evaporator through the duct and back to the evaporator. For the controlled cooling of the storage compartment, there is provided a continuously open supply or inlet port or opening connecting the duct or a branch of the duct with the compartment and an outlet port connecting the compartment with the duct at a point downstream from the inlet port. The outlet port is provided with a flow control means which is movable between a port closing and a port opening position and which is adapted to progressively block the duct upstream from the outlet port during movement to the port opening position and to unblock or open the duct during movement to the port closing position.

For a better understanding of the invention reference may be had to the accompanying drawings in which:

FIGURE 1 is a front elevation, with the closure members removed, of a refrigerator cabinet incorporating one embodiment of the present invention;

FIGURE 2 is a back elevation View, partially in section, of the cabinet of FIGURE 1 illustrating some of the duct structure employed in the practice of the present invention;

FIGURE 3 is a detailed sectional view of the flow control means employed to regulate the flow of air through a storage compartment of the refrigerator;

FIGURE 4 is a view similar to FIGURE 3 with the flow control means in an open position; and

FIGURE 5 is a front elevation view of refrigerator cabinet including a modification of the present invention.

While the invention is applicable to refrigerators containing one or more storage compartments, it will be described with specific reference to refrigerators comprising a freezer compartment and a fresh food compartment, both of which are cooled by forced air circulation.

With particular reference to FIGURES l and 2 of the drawing, there is shown one embodiment of the present invention in the form of a household refrigerator including an upper freezer compartment 1 and a lower fresh food compartment 2 separated from the freezer compartment by an insulated partition 3. The respective compartments are also separated from the outer shell or outer cabinet walls 4 and the spaces between the compartments and these walls are filled by means of insulation 5.

Both of the compartments are maintained at the desired refrigerating temperatures by means of a single evaporator 6 which operates at a below freezing temperature and is arranged within a housing 7 outside both of the compartments. In the illustrated embodiment of the invention, the evaporator 6 and its housing 7 are arranged within the insulated space to the rear of the freezer compartment 1. For the purpose of directing air cooled by the evaporator 6 into the two compartments 1 and 2, there is provided a forced air circulating system including a single air circulating means in the form of a centrifugal fan arranged within a scroll or housing 19 secured to the rear Wall of the housing 7 and driven by a motor 11. The blower scroll includes an inlet 12 in the rear wall through which air is withdrawn from the evaporator housing 7 and a pair of outlets 14 and 15. Most of the air flow passes through the outlet 14, which is larger than the outlet 15, and is directed to the freezer compartment 1 through a supply duct 16 above the freezer compartment 1 and into the freezer compartment through a plurality of outlet openings or slots (not shown) communicating di- :rectly with the interior of the freezer compartment. Air from the freezer compartment is returned to the housing 7 for cooling by the evaporator 6 through the air return opening 19 povided in the rear wall of the freezer compartment. Thus the air circuitry for cooling of the freezer compartment comprises in closed, series connection the housing 7, the fan, scroll 1t), duct 16, the freezer compartment 1 and return opening 19. It will be noted that there are no air flow controls in this freezer compartment air circuit and as evaporator 6 is designed to operate at subfreezing temperatures, a constant volume of sub-zero air can be supplied to the freezer compartment whenever the fan is operating so long as the proportioning of the air between the blower outlets 14 and 15 is not disturbed.

The air supply means for the fresh food compartment comprises a continuous duct 21 which is designed along its entire length to carry the maximum amount of air that may be required for refrigeration of the fresh food compartment 2 but which is located entirely outside of that compartment. This duct 21 has its inlet end 22 connected to the fan outlet 15 and its outlet end 23 connected directly to an opening 26 in the evaporator housing 7.

For the purpose of introducing a controlled amount of cooled air into the fresh food compartment 2, control means are provided for bypassing some of the air from the duct 21 into the fresh food compartment and back into the duct in such a manner that the total air flow through the duct 21 will not be significantly changed even though the amount of air flowing through the compartment 2 is varied. To this end, there is provided a branch duct 29 and an inlet or supply port or opening 27 for con- A ducting cooled air from the duct 21 into the compartment 2 and an air outlet port or opening 24 for returning air from the fresh food compartment 2 into the duct. The air outlet or return port 24 is downstream from the inlet port 2'7 with respect to the direction of flow of air through the duct 21.

In the embodiment of the invention shown in FIG- URES 1 and 2 of the drawing, there is provided a meat pan 28 in the lower portion of the fresh food compartment 2 and in order that maximum cooling of the contents of this pan can be obtained, the air supply or outlet opening 27 is arranged near the bottom of the compartment 2 immediately behind the meat pan. This air outlet port is connected to the duct 21 by means of the supply duct or side arm 29 which branches off from the main duct 21 upstream from the air return port 24.

For effecting a regulated flow of air into and through the compartment 2, there is provided an air flow control means in the form of a damper 30 associated with the air return port 24. This control means is so designed that as the port 24 is gradually opened to connect the interior of the compartment 2 with the duct 21, the duct 21 will be correspondingly restricted upstream from the port 24 thereby creating a pressure increase upstream from port 24 forcing air to flow from the duct 21 into the compartment 2 through the continuously open air inlet port 27.

In the illustrated embodiment of the invention and as is shown more in detail in FIGURES 3 and 4 of the drawing, the damper 30 is pivotally secured to the rear wall 31 of the fresh food compartment 2 by means of a hinge 33 which is at the upstream edge of the port 24. Control knob 34 is provided for regulating the position of the damper 30. By thus pivotally supporting the damper 30 at the upstream edge of the port 24, movement of the damper 30 from its closed position as illustrated in FIG- URE 3 of the drawing towards its open position in which it extends into the duct 21 as illustrated in FIGURE 4 of the drawing, the damper performs the dual function of partially or fully opening the port 24 to connect the interior of the compartment 2 to the duct 21 and at the same time correspondingly restricting or closing off the duct 21 upstream from the port 24. It is this restriction of the duct 21 upstream from the port 24 that increases the head pressure within that portion of the duct causing the cooled air to flow into the compartment 2 through the open port 27.

By this arrangement including the duct 21 capable of unrestrictedly conducting in a closed circuit the maximum amount of cooled air that may be required to cool the contents of the compartment 2 and the flow control arrangement including the damper 30 in the return port 24 for dividing the stream of air flowing through the duct 21 into a bypass stream which flows back to the evaporator housing through the remaining portions of the duct 21 and a fresh food compartment stream which enters the fresh food compartment through the port 27 and returns to the duct through the control port 24, the amount of air supplied to the compartment 2 does not affect the fan head pressures or the air fiow through the freezer compartment 1. In other words, the combination of the duct 21 having an open supply connection to the compartment 2 and the control damper 30 on the air return port 24, there is provided a means for regulating the volume of air flowing to the fresh food compartment of the refrigerator so that the temperature of that compartment can be varied without changing the air flow rates of the remaining portions of the system. With the damper 30 in the closed position there is little or no flow of air through the fresh food compartment and the air will follow the unrestricted path through the duct 21 and back to the evaporator housing 7. A close fit of the damper is not required since the closing of port 24 does not restrict air flow through duct 21 and hence does not affect the fan head or discharge pressure. When the damper is in the open position, that is, when the mere imum amount of cooled air is being directed through the fresh food compartment, the restriction in the duct 21 provided by the damper 30 causes an increase in the pressure within the bypass section 36 of the duct between ports 24 and 27 which will result in an air flow through the air supply port 27, the fresh food compartment 2 and back into the duct through the open port 24. Since the damper is located in such a manner that as the return or suction port 24 is gradually opened, the duct 21 is to the same extent closed off upstream from that port, it will be seen that by varying the damper position between full open and full closed, the relative proportion of air which passes through the fresh food compartment and hence the refrigeration of that compartment can be controlled substantially linearly and without altering the total amount of air passing through the fan outlet 15.

This system also has the advantage over a system in which there is no bypass for the fresh food compartment such as that provided by the intermediate section 36 of the duct 21 or in which the control damper is on the air inlet to the compartment in that the air pressures within the fresh food compartment aree substantially unaffected by the position of the means regulating the flow of air to that compartment. In other words, the intermediate section 36 of the supply duct 21 which provides for the flow of any portion of the air stream not directed through the compartment 2 will prevent the pressures in the fresh food compartment from changing upon an increase or decrease in the supply of air to that compartment. Thus, the pressures in that compartment will not increase or decrease to a point which might cause gasket leakage or leakage of air from or into the fresh food compartment through other openings in the compartment liner.

FIGURE 5 illustrates a modification of the present invention in which the same air flow supply and control means is provided in a refrigerator in which the freezer compartment 40 is on the bottom and the fresh food storage compartment 41 is at the top of the cabinet. In FIGURE 5, similar parts or parts performing similar functions are given the same reference numerals as are used in connection with the embodiment illustrated in FIGURES 1-4 of the drawing. It will be noted that the duct 21 is U-shaped and extends upwardly outside and along one side of the rear wall 42 of the fresh food compartment 41 and downwardly along the other side. The air supply or discharge opening 27 is provided near the bottom of the fresh food compartment and to the rear of the meat pan 28 while the suction or return port 24 is positioned adjacent the upper part of the fresh food compartment 41 and the flow of air through the compartment is controlled in the same manner by means of the damper 30 associated with the port 24. The damper 30, in this modification is pivoted at the top of port 24, that is at the upstream edge thereof. The remaining components of the cooling system including the evaporator 6 and its housing are positioned rearwardly from the freezer compartment 4% in the same manner as they are positioned with reference to the embodiment illustrated in FIGURES 1 and 2.

While there has been shown and described specific embodiments of the present invention, it is to be understood that the invention is not limited thereto and it is intended by the appended claims to cover all modifications within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A refrigerator comprising a storage compartment, an evaporator housing, an evaporator mounted in said evaporator housing, a duct defining an air flow path outside said storage compartment for the flow of air from said evaporator housing, through said duct and back to said evaporator housing, means for providing forced circulation of air through said duct, a continuously open inlet port connecting said duct with said storage compartment, an outlet port connecting said storage compartment with said duct as a point downstream from said inlet port, and a flow control means for said outlet port movable between a port closing position and port opening position, said means progressively blocking said duct upstream from said outlet port during movement to said port opening position.

2. A refrigerator comprising a storage compartment, an evaporator housing, an evaporator mounted in said evaporator housing, a duct arranged along a wall of said storage compartment defining an air flow path outside said compartment for the flow of air from said evaporator housing, through said duct and back to said evaporator housing, means for providing forced circulation of air through said duct, an unrestricted air inlet port connecting said duct with said storage compartment, an outlet port connecting said storage compartment with said duct at a point downstream from said inlet port and a flow control means associated with said outlet port and movable between a port closing position and a port opening position, said flow control means blocking said duct upstream from said outlet port upon movement thereof to said port opening position.

3. A refrigerator comprising a storage compartment, an evaporator housing, an evaporator mounted in said evaporator housing, a duct defining an air path outside said storage compartment for the flow of air from said evaporator housing, through said duct and back to said evaporator housing, means for providing forced circulation of air over said evaporator and through said duct, a continuously open inlet port connecting said duct with said storage compartment, an outlet port connecting said storage compartment with said duct at a point downstream from said inlet port and a how control means for controlling the flow of air through said outlet port, said flow control means being movable between a port closing position and port opening position, said flow control means extending across said duct upstream from said outlet port when in said port opening position to block the flow of air through the portion of said duct between said ports.

4. A refrigerator comprising a fresh food compartment for the storage of unfrozen foods, a freezer compartment for the storage of frozen foods, an evaporator housing, an evaporator mounted in said evaporator housing, an air flow system including a single fan for circulating air streams over said evaporator and through said compartments, said system comprising means defining a first air flow path for circulating a stream of air from said evaporator housing through said freezer compartment and b ack to said evaporator housing and means defining a second air flow path for circulating another air stream from said evaporator housing through a duct positioned outside said fresh food compartment and b ack to said evaporator housing, an open, uncontrolled, inlet port connecting said duct with fresh food compartment, an \outlet port connecting said fresh food compartment with said duct at a point downstream from said inlet port and an air flow control means for said outlet port movable between \a port closing and port opening position and adapted to progressively block said duct upstream from said outlet port during movement to said port opening position.

References Cited in the file of this patent UNITED STATES PATENTS 2,467,427 Green Apr. 19, 1949 2,863,300 Murphy Dec. 9, 1958 2,907,180 Mann Oct. 6, 1959 2,997,857 Clark Aug. 29, 1961 3,023,589 Jacobs Mar. 6, 1962 3,048,024 Jacobs Aug. 7, 1962 3,048,985 Long Aug. 14, 1962 3,050,956 Mann Aug. 28, 1962 3,050,961 Mann Aug. 28, 1962 3,070,973 OConnell Jan. 1, 1963 

1. A REFRIGERATOR COMPRISING A STORAGE COMPARTMENT, AN EVAPORATOR HOUSING, AN EVAPORATOR MOUNTED IN SAID EVAPORATOR HOUSING, A DUCT DEFINING AN AIR FLOW PATH OUTSIDE SAID STORAGE COMPARTMENT FOR THE FLOW OF AIR FROM SAID EVAPORATOR HOUSING, THROUGH SAID DUCT AND BACK TO SAID EVAPORATOR HOUSING, MEANS FOR PROVIDING FORCED CIRCULATION OF AIR THROUGH SAID DUCT, A CONTINUOUSLY OPEN INLET PORT CONNECTING SAID DUCT WITH SAID STORAGE COMPARTMENT, AN 